Sheet material of relatively large dimension and area, such as engineering drawings, blueprints, building and construction specifications, maps, charts, and various other types of drawings and printed matter are relatively difficult to file. Several prior methods of filing such sheet material have included vertical suspension of individual sheets from a horizontal crossbar, vertical suspension of multiple sheets held in a friction binder from a horizontal support bar, a vertical arrangement of square section compartments in which the sheet material was rolled into a cylinder and inserted in a compartment, and filing such sheet material in a flat horizontal drawer. Often the support bar was provided in a cabinet construction, the support bar being either fixed in its location in the cabinet or being mounted on a tracking mechanism which would permit the support bar to be moved outwardly toward the cabinet opening to facilitate disengagement and engagement of the vertically suspended material with the support bar.
One example of a cabinet construction for vertical filing of sheet material is described in my U.S. Pat. No. 3,994,547 in which the support bar is provided with a configuration which so mates with a configuration on a suspension means that the sheet material may be moved horizontally into interengagement with the support bar and held in level horizontal position.
There have been numerous configurations of support bars and suspension members for hanging sheet material in vertical planes and for attempting to hold the sheet material in level position while at the same time attempting to facilitate engagement and disengagement of the suspension member with the support bar. Such numerous constructions are described and shown in the following patents: Austrian Pat. No. 226,195; Austrian Pat. No. 229,265; German Pat. No. 1,110,136; Zippel Pat. Nos. 3,208,457, 3,275,004; Stillwell U.S. Pat. No. 1,066,543; Butts U.S. Pat. No. 3,890,197; Johansson U.S. Pat. No. 3,666,226; German Pat. No. 1,126,356.
In addition, it was sometimes found to be desirable to provide a support bar configuration having multipurposes; that is, the ability to support different types of vertical filing systems. For example, it was desired that a single cabinet with a support bar therein be adapted for use for vertical filing of multiple sheets of material held in a binder, single sheets of material, and the suspension from the bar of multicompartmented vertically arranged filing structures for roll stored drawings. Thus, the configuration of the support bar was characterized by its adaptability to different types of vertical filing. Different filing systems, as mentioned above, also created load problems on the support bar and such a multipurpose support bar was required to be sufficiently strong to reduce to a minimum bending of the bar between its support points. It will be understood that such a support bar may support as much as 750 lbs. or more of sheet material.